This invention relates to a milling attachment which is adapted to be mounted to the cross slide of any standard metalworking lathe such that milling operations or other operations such as boring, polishing, sawing, grinding and tapping can be performed on a workpiece which is held in the chuck or between the chuck and tailstock.
One of the primary concerns with milling attachments for lathes is the ability to position them accurately relative to the workpiece and assure that they remain in this position during the milling operation. Since the attachment is normally mounted on either the cross slide or carriage of the lathe and the attachment spindle raised or lowered to achieve the desired vertical positioning, one technique for assuring that the vertical position of the tool does not change during the milling operation is to lock the spindle block or housing to the supporting structure. In U.S. Pat. No. 2,497,735 to McCullough, for example, the spindle housing is locked in adjusted vertical position by means of wedge-shaped members drawn together by a threaded rod against two of the supporting posts. It is desirable however, from the standpoint of accuracy and precision in positioning, to minimize distortion and lateral movement of the spindle housing or block and the vertical support means as they are locked together. Continued accuracy over the life of the machine also requires that as little wear as possible occurs between these two elements and that any wear which does occur can be compensated for.
A further consideration relating to milling attachments for lathes is the amount of space they occupy when mounted. Accordingly, a desirable feature is compactness and efficient use of space without sacrificing accuracy. Not only does this feature permit the use of the attachment with a wide variety of sizes and configurations of lathes, but permits other lathe operations to be performed without completely removing the milling attachment.
Further examples of prior art milling attachments are U.S. Pat. No. 2,453,315 to Harbison and British Pat. No. 676,719 to Powell.